Dishwasher appliance with temperature actuated ventilation

ABSTRACT

A ventilation system for a dishwashing appliance is provided. An actuator that is activated by heat provided by operation of the dishwasher is used to move a gate so as to provide an open position where one or more openings are created though which heat and fluid may be vented from the wash chamber. Upon cooling the actuator, it allows the gate to move to a closed position blocking the flow of heat and fluid from the wash chamber. The application of heat or cooling changes the shape of the actuator so as to provide for the positioning of the gate.

FIELD OF THE INVENTION

The subject matter of the present invention relates to the ventilation of a dishwasher appliance.

BACKGROUND OF THE INVENTION

Modern dishwashers typically include a wash chamber where e.g., detergent, water, and heat can be applied to clean food or other materials from dishes and other articles being washed. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle, rinse cycle, and a drying cycle. A pre-wash cycle may also be included as part of the normal cleaning cycle or as an option for particularly soiled dishes.

In one or more of these cycles, particularly during the drying cycle, it may be desirable to allow heated fluid—typically steam—to be vented from the wash chamber. Such venting allows e.g., for the removal of moisture from the dishes and helps dissipate heat from the drying cycle. Venting may also be desirable near e.g., the end of the wash cycle.

Conversely, it is also desirable to retain fluids and heat during other parts of the cleaning process. For example, during most of the wash cycle, cleaning can be improved by keeping the wash chamber sealed so as to retain heat energy while a heated mixture of water and detergent is sprayed against the dishes and other articles. Maintaining a closed chamber during some portions of the pre-wash and wash cycle can also be necessary in order to prevent fluid from being ejected.

Conventionally, one or more vents have been provided near the top of the front door of the dishwasher to allow for the escape of fluid from the wash chamber. The flow of fluid through such vents is commonly controlled through a curtain or other cover that is driven by a motor connected through a drive mechanism. The motor must be electrically powered and activated at appropriate times during the cleaning process. As such, this conventional configuration typically adds expense to the manufacture and maintenance of a dishwashing appliance.

Accordingly, a system for venting a dishwasher appliance would be useful. More particularly, a system for venting a dishwasher appliance that does not rely upon e.g., a mechanism driven by an electric motor would be beneficial. Such as system that can also be activated at appropriate times during the cleaning process would also be useful.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one exemplary embodiment, the present invention provides a dishwasher appliance having a a chamber for the receipt of articles for cleaning A door is included for selectively opening and closing the dishwasher appliance. The door has an interior wall defining a first aperture for the egress of fluid from the chamber. A vent controls the egress of fluid from the chamber. The vent is received into the door. The vent includes a movable gate defining a second aperture for the egress of fluid from the chamber. The movable gate is positioned adjacent to the first aperture of the interior wall of the and has a closed position wherein the gate blocks the flow of fluid from the chamber and an open position where the second aperture of the movable gate is aligned with the first aperture of the door such that fluid can flow from the chamber. An actuator is positioned in contact with the movable gate. The actuator is configured for moving the movable gate into the open position with heating of the actuator and is configured for allowing the movable gate to move into the closed position with cooling of the actuator.

In still another exemplary embodiment, the present invention provides a dishwasher appliance including a chamber for the receipt of articles for cleaning; a door for selectively accessing the chamber, the door defining a first plurality of apertures for the venting of fluid from the chamber. A gate is connected with the door. The gate defines a second plurality of apertures for the venting of fluid from the chamber. The gate is movable between a closed position and an open position. The flow of fluid from the chamber through the gate is blocked in the closed position and allowed in the open position by the alignment of the first and second plurality of apertures. An actuator is in mechanical communication with the gate. The actuator is configured for positioning the gate between the closed position and the open position in response to heating and cooling of the actuator.

In another exemplary aspect, the present invention provides a method for venting a chamber of a dishwasher. The dishwasher has a gate for controlling the flow of fluid out of the chamber. The method includes the steps of heating an actuator that is connected with the gate; moving the gate using changes in the shape of the actuator so as place the gate into a position that allows for the flow of fluid out of the chamber; cooling the actuator that is connected with the gate; and, changing the shape of the actuator while moving the gate to another position that blocks the flow of fluid out of the chamber.

In still another exemplary embodiment, the present invention provides a vent mechanism for venting an enclosed space. The mechanism includes a wall portion defining a first aperture for the release of fluid from the enclosed space. A movable gate is attached to the wall portion proximate the first aperture. The movable gate defines a second aperture for the release of fluid from the enclosed space. The movable gate has a closed position wherein the movable gate blocks the flow of fluid from the enclosed space and an open position where the second aperture of the movable gate is aligned with the first aperture of the wall portion such that fluid can flow from the enclosed space. An actuator is positioned in contact with the movable gate. The actuator is configured for moving the movable gate into the open position upon being heated by a fluid from the enclosed space. The actuator is configured for allowing the movable gate to move into the closed position with cooling of the actuator.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 provides a front, perspective view of an exemplary dishwashing appliance of the present invention.

FIG. 2 provides a side, cross-sectional view of the exemplary embodiment of FIG. 1.

FIG. 3 illustrates the rear or interior side of an exemplary embodiment of a door as may be used with the dishwashing appliance of FIGS. 1 and 2.

FIG. 4 is a perspective view of an exemplary embodiment of the present invention shown in an open position.

FIGS. 5 and 6 are front and rear views, respectively, of the exemplary embodiment of FIG. 4.

FIGS. 7 and 8 are rear views of another exemplary embodiment showing an open and closed position, respectively.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a ventilation system for a dishwashing appliance. An actuator that is activated by heat provided by operation of the dishwasher is used to move a gate so as to provide an open position where one or more openings are created though which heat and fluid may be vented from the dishwasher. Upon cooling the actuator, it allows the gate to move to a closed position blocking the flow of heat and fluid from the wash chamber. The application of heat or cooling changes the shape of the actuator so as to provide for the positioning of the gate. For example, the actuator may be constructed from a shape memory alloy as will be further described. The ventilation system of the present invention may also be used in non-appliance applications as well for the venting of an enclosed place containing a fluid that can provide for heating of the actuator.

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIGS. 1 and 2 depict an exemplary domestic dishwasher 100 that may be configured in accordance with aspects of the present disclosure. For the particular embodiment of FIG. 1, the dishwasher 100 includes a cabinet 102 having a tub 104 therein that defines a wash chamber 106. The tub 104 includes a front opening (not shown) and a door 120 hinged at its bottom 122 for movement between a normally closed vertical position (shown in FIGS. 1 and 2), wherein the wash chamber 106 is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher. Latch 123 is used to lock and unlock door 120 for access to chamber 106.

Upper and lower guide rails 124, 126 are mounted on tub side walls 128 and accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in FIG. 2). Each rack 130, 132 is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2) in which the rack is located inside the wash chamber 106. This is facilitated by rollers 135 and 139, for example, mounted onto racks 130 and 132, respectively. A silverware basket (not shown) may be removably attached to rack assembly 132 for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks 130, 132.

The dishwasher 100 further includes a lower spray-arm assembly 144 that is rotatably mounted within a lower region 146 of the wash chamber 106 and above a tub sump portion 142 so as to rotate in relatively close proximity to rack assembly 132. A mid-level spray-arm assembly 148 is located in an upper region of the wash chamber 106 and may be located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 may be located above the upper rack 130.

The lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 are fed by a fluid circulation assembly 152 for circulating water and dishwasher fluid in the tub 104. The fluid circulation assembly 152 may include a pump 154 located in a machinery compartment 140 located below the bottom sump portion 142 of the tub 104, as generally recognized in the art. Each spray-arm assembly 144, 148 includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in rack assemblies 130 and 132. The arrangement of the discharge ports in spray-arm assemblies 144, 148 provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly 144 provides coverage of dishes and other dishwasher contents with a washing spray.

The dishwasher 100 is further equipped with a controller 137 to regulate operation of the dishwasher 100. The controller may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.

The controller 137 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, the controller 137 may be located within a control panel area 121 of door 120 as shown. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher 100 along wiring harnesses that may be routed through the bottom 122 of door 120. Typically, the controller 137 includes a user interface panel 136 through which a user may select various operational features and modes and monitor progress of the dishwasher 100. In one embodiment, the user interface 136 may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface 136 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface 136 may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface 136 may be in communication with the controller 137 via one or more signal lines or shared communication busses.

FIG. 3 provides a rear view of door 120 with interior wall 156. By way of example, door 120 includes a tray 158 for the receipt of dishwashing detergent and a port 160 for rinse cycle additives. Near top 162, a vent 164 is received into door 120 and provides for controlling the egress of fluid from chamber 106 as will be further described.

It should be appreciated that the invention is not limited to any particular style, model, or other configuration of dishwasher, and that the embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. For example, instead of the racks 130, 132 depicted in FIG. 1, the dishwasher 100 may be of a known configuration that utilizes drawers that pull out from the cabinet and are accessible from the top for loading and unloading of articles. Other configurations may be used as well.

Returning to FIG. 3, vent 164 includes a first plurality of apertures 166 through which a fluid such as e.g., steam or air may flow to escape from chamber 106. After entering vent 164 through apertures 166, the fluid is removed from openings that may be located e.g., along the top edge 168 of door 120. The particularly configuration—including the number and shape—of apertures shown in FIG. 3 is provided by way of example only. Multiple other placements and shapes may be used instead of the first plurality of apertures 166. Additionally, a single aperture may be used as well. Such apertures, including e.g., the first plurality of apertures 166, may also be defined by interior wall 156 of door 120. Using the teachings disclosed herein, one of skill in the art will understand that a variety of other configurations for the arrangement of apertures to release fluid from wash chamber 106 may be provided as well.

FIG. 4 provides a perspective view of vent 164 in the open position. Vent 164 includes a movable gate 170 that defines a second plurality of apertures 172 for the venting of fluid from wash chamber 106. FIG. 5 provides a front view of vent 164 in the closed position with the first plurality of apertures 166 defined by interior wall 156 shown in dashed lines and the second plurality of apertures 172 defined by movable gate 170 shown in solid lines. FIG. 6 provides a rear view of vent 164 in which only the first plurality of apertures 166 defined by interior wall 156 are shown.

Referring now to FIGS. 4 through 6, gate 170 is received into a pair of opposing guides 174 defined by interior wall 156. The side edges 176 of gate 170 can slide back and forth along opposing guides 174 so as to open or close vent 164. As such, gate 170 can move between the open position of FIG. 4 where fluid may escape chamber 106 by passing through both the first plurality of apertures 166 and the second plurality of apertures 172. More specifically, and by way of example, when gate 170 is in the closed position as shown in FIG. 5, first aperture 166 a is not aligned with second aperture 172 a and the flow of fluid from wash chamber 106 is blocked. When gate 170 is in the open position shown in FIG. 5, first aperture 166 a and second aperture 172 a are aligned such that fluid may flow from wash chamber 106.

Vent 166 includes an actuator 178 positioned in a compartment 180 and in contact with a bottom edge 182 of movable gate 170. During operation of dishwasher 100, as heated fluids such as wash liquids and/or steam are created, this heat will be transferred to actuator 178. Actuator 178 is constructed from material—such as shape memory alloy—that changes shape upon being heated. Shape memory alloys can be constructed, e.g., from copper-zinc-aluminium-nickel, copper-aluminium-nickel, and nickel-titanium alloys. Shape memory alloys can also be created from zinc, copper, gold and iron. For example, for this particular exemplary embodiment, actuator 178 is constructed from a two-way, shape memory alloy. In general, a two-way, shape memory alloy can “remember” two different shapes—one shape at cooler temperatures and another shape at a warmer temperatures. Through heating or cooling, the two-way, shape memory allow can be caused to shift between these two shapes.

Accordingly, as shown in FIG. 4, upon being heated by e.g., warm or hot fluid in the chamber 106 of dishwasher 100, the curvature of actuator 178 increases. This change in shape raises gate 170 from the closed position of FIG. 5 to the open position of FIG. 4 as indicated by arrows O in FIG. 4. For example, as a heated fluid is used during a wash or drying cycle, through heat transfer to the gate from the fluid, gate 170 will be moved into the open position as actuator 178 is heated.

Conversely, as shown in FIG. 5, upon cooling of actuator 178, its curvature decreases so as to lower gate 170 from the open position of FIG. 4 to the closed position of FIG. 5 as indicated by arrows C in FIG. 5. Such cooling may occur, e.g., after the drying cycle. Upon completing of the drying cycle, chamber 106 no longer receives heat and begins to cool. Eventually, actuator 178 will also cool and thereby return to its original shape shown in FIG. 5—thereby lowering gate 170 so that the flow of fluid from chamber 106 is now blocked. The lowering of gate 170 may occur by force of gravity and/or springs or other mechanisms may be used to force such closure as actuator 178 cools.

For example, FIGS. 7 and 8 illustrate another exemplary embodiment of a vent 164 similar to the exemplary embodiment of FIGS. 4-6. However, the vent of FIGS. 7 and 8 includes a spring 184 positioned within one of the opposing guides 174. Spring 184 is held in place by a pin 182 that is fixed at end 186 into interior wall 156 and slides within a cavity 188 along second end 190. When door 170 is raised (arrows O) by the heating of actuator 178, spring 184 is compressed as shown in FIG. 7. Upon cooling of actuator 178, causing it to return to its original shape, door 170 is lowered (arrows C) as shown in FIG. 8 by the decompression of spring 184. The embodiment of FIGS. 7 and 8 can be useful for orientations of vent 164 where gravity may be available to assist in moving the gate 170 to a closed position. In addition, this exemplary embodiment can be applied when actuator 178 is constructed from a one-way, shape memory alloy. With a one-way shape memory alloy, actuator 178 will increase its curvature so as to move gate 170 upon heating as shown in FIG. 7. However, as actuator 178 cools, it will remain in such increased curvature condition without an external force to return actuator 178 to its original shape as depicted in FIG. 8. Accordingly, spring 184 provides a compressive force against the top edge 192 of gate 170 that moves it to a closed position and restores actuator 178 to its original shape before being heated. Although only one spring 184 is shown along a guide 174, it will be understood that a pair of springs 184—one in each of the pair of opposing guides 174—could be used as well.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

1. A dishwasher appliance, comprising: a chamber for the receipt of articles for cleaning; a door for selectively opening and closing the dishwasher appliance, said door having an interior wall defining a first aperture for the egress of fluid from said chamber; a vent for controlling the egress of fluid from said chamber, said vent received into said door, said vent comprising a movable gate defining a second aperture for the egress of fluid from said chamber, said movable gate positioned adjacent to the first aperture of the interior wall of said door, said movable gate having a closed position wherein said movable gate blocks the flow of fluid from said chamber and an open position where the second aperture of said movable gate is aligned with the first aperture of said door such that fluid can flow from said chamber; and, an actuator positioned in contact with said movable gate, said actuator configured for moving said movable gate into the open position with heating of said actuator, said actuator configured for allowing said movable gate to move into the closed position with cooling of said actuator.
 2. A dishwasher appliance as in claim 1, wherein said actuator comprises a shape-memory alloy.
 3. A dishwasher appliance as in claim 1, wherein said actuator comprises a two-way, shape memory alloy.
 4. A dishwasher appliance as in claim 1, wherein said door defines a pair of opposing guides into which opposing sides of said movable gate are received such that said movable gate may slide along said opposing guides between the closed position and the open position.
 5. A dishwasher appliance as in claim 1, wherein said movable gate has a top edge and a bottom edge, and wherein said actuator is in contact with the bottom edge of said movable gate.
 6. A dishwasher appliance as in claim 5, further comprising a spring in contact with the top edge of said movable gate, said spring having a compressed state when said movable gate is in the open position.
 7. A dishwasher appliance as in claim 1, wherein said door defines a pair of opposing guides into which opposing sides of said movable gate are received such that said movable gate may slide along said opposing guides between the closed position and the open position; wherein said movable gate has a top edge and a bottom edge, and wherein said actuator is in contact with the bottom edge of said movable gate; and, further comprising a spring in contact with the top edge of said movable gate, said spring having a compressed state when said movable gate is in the open position.
 8. A dishwasher appliance as in claim 1, wherein the first aperture is located near a top portion of said door.
 9. A dishwasher appliance, comprising: a chamber for the receipt of articles for cleaning; a door for selectively accessing said chamber; said door defining a first plurality of apertures for the venting of fluid from said chamber; a gate connected with said door, said gate defining a second plurality of apertures for the venting of fluid from said chamber, said gate movable between a closed position and an open position, wherein the flow of fluid from said chamber through said gate is blocked in the closed position and allowed in the open position by the alignment of said first and second plurality of apertures; and, an actuator in mechanical communication with said gate, said actuator configured for positioning said gate between the closed position and the open position in response to heating and cooling of the actuator.
 10. A dishwasher appliance as in claim 9, wherein said actuator comprises a shape-memory alloy.
 11. A dishwasher appliance as in claim 9, wherein said actuator comprises a two-way, shape memory alloy.
 12. A dishwasher appliance as in claim 9, wherein said door defines a pair of opposing guides into which opposing sides of said movable gate are received such that said movable gate may slide along said opposing guides between the closed position and the open position.
 13. A dishwasher appliance as in claim 12, further comprising a spring configured for pressing upon a top edge of said door to return said door to the closed position.
 14. A dishwasher appliance as in claim 12, further comprising a pair of springs configured for pressing upon a top edge of said door to return said door to the closed position.
 15. A method for venting a chamber of a dishwasher, the dishwasher having a gate for controlling the flow of fluid out of the chamber, the method comprising the steps of: heating an actuator that is connected with the gate; moving the gate using changes in the shape of the actuator so as place the gate into a position that allows for the flow of fluid out of the chamber; cooling the actuator that is connected with the gate; and, changing the shape of the actuator while moving the gate to another position that blocks the flow of fluid out of the chamber.
 16. A method for venting a chamber of a dishwasher as in claim 15, wherein said heating step comprises contacting said actuator with heated fluid from the chamber.
 17. A method for venting a chamber of a dishwasher as in claim 15, wherein said heating step comprises transferring from fluid in the chamber to the actuator.
 18. A method for venting a chamber of a dishwasher as in claim 15, wherein said actuator is a shape memory alloy.
 19. A method for venting a chamber of a dishwasher as in claim 15, wherein said step of changing further comprises pressing upon the gate using a compressed spring.
 20. A vent mechanism for venting an enclosed space, the mechanism comprising: a wall portion defining a first aperture for the release of fluid from the enclosed space; a movable gate attached to said wall portion proximate the first aperture, said movable gate defining a second aperture for the release of fluid from said enclosed space, said movable gate having a closed position wherein said movable gate blocks the flow of fluid from the enclosed space and an open position where the second aperture of said movable gate is aligned with the first aperture of said wall portion such that fluid can flow from the enclosed space; and, an actuator positioned in contact with said movable gate, said actuator configured for moving said movable gate into the open position upon being heated by a fluid from the enclosed space, said actuator configured for allowing said movable gate to move into the closed position with cooling of said actuator. 